How do you calculate the time constant of an RL circuit in the transient response?

τ = L / R

where:

τ is the time constant in seconds (s)

L is the inductance of the inductor in henries (H)

R is the resistance of the resistor in ohms (Ω)

The time constant (τ) represents the time it takes for the transient response of the RL circuit to reach approximately 63.2% of its final or steady-state value.

Transient response in an RL circuit refers to the behavior of the circuit when it is first energized or when there is a sudden change in the input voltage. The response involves the inductor's current rising or falling towards its final value in the presence of resistance. The time constant is a crucial parameter to understand how quickly the current in the inductor reaches a stable state during this process.